1. Field of the Invention
The present invention relates to a propeller apparatus used in fluid, such as air or water, to generate propulsion and, more particularly, to a propeller apparatus designed to effectively prevent rotating energy loss caused by a formation of a vortex within the apparatus and to allow the rotating energy of a propeller to entirely act in the propulsion direction and to maximize energy efficiency of a drive engine through using both heat dissipated from the radiation fins of the engine and hot exhaust gas discharged from the exhaust ports of the engine since the drive engine is installed within the tapered nozzle part of the barrel and to accomplish optimal propulsion.
2. Description of the Prior Art
As well known to those skilled in the art, propellers or screws have been typically used in air and water to generate desired propulsion. In a conventional propeller apparatus, it is necessary to design the propeller to increase fluid flow rate during its rotating action, and so the propeller is forced to have a large blade angle and to rotate at a high speed. However, such a large blade angle of a propeller necessarily induces large fluid resistance acting on the blades of the propeller during a rotating action of the propeller, and undesirably overloads the drive means for the propeller. FIG. 5 is a schematic view showing an operation of a conventional propeller apparatus. As shown in the drawing, a propeller 01 is set on the rotating shaft 03 of a drive engine 02 and is rotated in an open space while forming a swirl in fluid when it is rotated to generate propulsion. Such a swirl of fluid increases the centrifugal force of the propeller, thus undesirably expelling the fluid in a centrifugal direction of the propeller. This finally induces rotating energy loss of the propeller due to, for example, the frictional resistance acting on the blades of the propeller, thus preventing the propeller apparatus from forming desired propulsion. When the fluid is expelled in the centrifugal direction of the propeller as described above, a vortex is formed in the fluid, thus resulting in additional energy loss. Such additional energy loss due to the vortex cooperates with the rotating energy loss due to the frictional resistance to further reduce operational efficiency of the propeller apparatus.
In a brief description, the conventional propeller apparatus has a structural defect in that it undesirably induces a large quantity of energy loss during a conversion of the rotating force of the propeller into propulsion.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a propeller apparatus, in which a plurality of propellers are regularly and concentrically set within a cylindrical barrel to form a multi-stage propeller assembly, thus increasing the flow rate of outlet fluid ejected from the barrel, and in which the drive means for the propellers is set within the barrel, thus increasing the temperature and pressure of the fluid, using the thermal energy dissipated from the drive means, thus effectively forming desired strong propulsion from the rotating energy of the propellers.
In order to accomplish the above object, the present invention provides a propeller apparatus, comprising a barrel having a cylindrical actuation part and a tapered nozzle part, the tapered nozzle part integrally extending from the cylindrical actuation part while being reduced in its diameter in a direction from one end around the actuation part to the other end, a drive engine installed within the tapered nozzle part, with the drive shaft of the engine axially extending within the actuation part, a plurality of propellers regularly set along the drive shaft to form a multi-stage propeller assembly, and a plurality of fixed radial blade units regularly set between the propellers.